1. Field
The present invention relates to steel frame building and more particularly to such building that are designed to facilitate the precise location of the column which results in rapid, low cost building assembly without the need for cutting, redrilling or welding of any of the structural members.
2. Prior Art
There are a number of prior art steel buildings containing features designed to facilitate the assembly of these buildings as evidence by the patents reference below.
U.S. Pat. No. 4,342,177 illustrates a steel frame building in which the roof beams are connected to the columns by means of a plate using bolts. However, this attachment does not allow for height adjustment. The columns are C-shaped and cannot be easily slipped over a foundation assembly.
U.S. Pat. No. 5,577,353 illustrates a steel frame building in which the components of the trusses are held together with pre-drilled truss plates and bolts and the trusses are attached to the columns by means of pre-drilled plates and bolts. However, there is no provision for height adjustment at the column attachment. There is no provision to allow the trusses to be conveniently broken in two for transport and there is no provision to allow the columns to slip over the foundation members.
U.S. Pat. No. 5,979,119 illustrates an assembly of structural building components designed to be attached to a column. The attachment method permits the adjustment of the angle at which beams are connected however, height adjustment is achieved by clamping rather than positive bolting.
In prior art structures, the mounting system for columns was typically bolts placed in the concrete footer before the concrete had set. This is shown in FIG. 12, where a column 31A is connected to a flange 32A. The flange is secured to a footer 35 by means of bolts 34. The position of the bolts is usually determined by a steel tape measure, which usually results in location errors in the order of xc2xc to xc2xd inch. These errors require the framing members to be cut and fitted on the site, a slow and costly process. The reason for these errors are many and include the use of a tape measure, the use of aggregate in the concrete which makes it difficult to precisely set a bolt in place and the fact that the bolt is let stand while the concrete sets up. During the set up process, the bolt can be moved by a variety of forces including the bolt""s own weight, pent up pressure points created by forcing the bolt into the concrete, wind, rain and inadvertent contact by workmen.
In the prior art assembly procedure, once the concrete has set up and the bolts have been secured in the concrete, the next task is the lifting of the column over and on to these bolts. The column typically has a lower flange with holes used to accommodate the bolts and connect the column to the footing. The column with its flange is lowered down on to the bolts and nuts are used to secure the bolts to the flange. However, at this time, with the column suspended in the air, it is difficult to correct for the horizontal plane location errors of the bolts, while at the same time connect the column to the bolts and erect the column in a perfectly vertical position. This prior art assembly procedure does not lend itself to precisely locating the column and results in building members not fitting together and requiring time consuming and costly redrilling and cutting on the job site to complete the assembly of the building.
All of the above mentioned disadvantages of the prior art are addressed and overcome in the present invention which is described below.